[Amended] Material event report (merger) (subsidiary)

What happened

AMENDMENT (August 26, 2026) 1. Disclosure document subject to amendment: Material event report (merger decision) 2. Original submission date of the disclosure document subject to amendment: August 25, 2026 3. Amended item Item: 18. Other important matters relevant to investment decisions Reason for amendment: Amendment following filing of the securities registration statement Before amendment: "For further details, please refer to SK Innovation Co., Ltd.'s securities registration statement (merger) to be filed later." After amendment: "For further details, please refer to SK Innovation Co., Ltd.'s securities registration statement (merger) filed on August 26, 2026."

Material event report / Exchange reporting obligation matter To the Financial Services Commission / Korea Exchange August 25, 2026 Company name: SK Innovation Co., Ltd. CEO: Jang Yong-ho, Choo Hyung-wook Head office address: 26 Jongno, Jongno-gu, Seoul (Seorin-dong SK Building) Phone: 02-2121-5114 Website: http://www.skinnovation.co.kr Preparer: Bae Gi-rak, Head of Financial Planning Office, Phone 02-2121-5114

Company merger decision

1. Merger method SK Innovation Co., Ltd. will absorb its subsidiary SK IE Technology Co., Ltd. - Surviving company: SK Innovation Co., Ltd. - Dissolving company: SK IE Technology Co., Ltd. - Merger type: Small-scale merger

2. Purpose of merger The merging companies are pursuing this merger to secure financial stability, proactively mitigate business and financial risk, and improve operating efficiency through business restructuring, which is expected to strengthen the competitiveness of the separator (battery membrane) business.

3. Material effects of the merger 1. Effect on management: The surviving company is SK Innovation Co., Ltd., and SK IE Technology Co., Ltd. will be dissolved after the merger, with the surviving company succeeding to its business as is. As of the date of this report, the surviving company's largest shareholder is SK Co., Ltd., holding 52.09% of common shares, and the dissolving company's largest shareholder is the surviving company itself, holding 53.35% of common shares. After the merger, the surviving company's largest shareholder's common-share stake is expected to change to 50.74%, with no change in the identity of the largest shareholder. 2. Effect on finances: As the dissolving company is already a consolidated subsidiary of the surviving company, the merger's effect on consolidated financial position is expected to be limited from a consolidated perspective; however, as the dissolving company's non-controlling interests are attributed to the surviving company upon merger, the effect of the dissolving company's net loss may be amplified in the short term, with a potentially larger negative effect on profit attributable to the controlling shareholder, and actual cash outflow may occur depending on the scale of appraisal-right exercise. In the medium to long term, financial stability and cash-generating capacity are expected to improve from reduced duplicate costs and financing costs, including cost savings from eliminating duplicate business functions and lower interest expense based on the surviving company's credit standing, with further profitability improvement expected if the EV market recovers and the ESS separator business expands. 3. Effect on operations: Upon this merger, the separator business will be incorporated into the surviving company. Before the merger, there was a risk that continued financial instability at the dissolving company could disrupt separator supply and in turn disrupt SK On Co., Ltd.'s battery production; after merging with a financially stable surviving company, the separator production and supply system is expected to be operated more effectively. The merger is also expected to improve operating efficiency, reduce costs, and combine the surviving company's R&D capability with the dissolving company's product development capability to strengthen business competitiveness, including expanded sales of ESS separators. 4. Effect on shareholder value: The merging companies conducted a multi-faceted review to protect both companies' shareholder value, calculating the merger ratio fairly under the Financial Investment Services and Capital Markets Act and related regulations. As this is a merger between listed companies, the merging companies calculated the merger value and ratio using the market-price method, with no premium or discount applied. Common shareholders of record of the dissolving company as of the record date for allotment of new merger shares will receive 0.1174540 shares of the surviving company's common stock for each dissolving-company common share held, except for shares held by the surviving company or treasury shares arising from appraisal-right exercise. The surviving company will issue a total of 4,481,300 new merger shares, equal to approximately 2.6% of its total issued shares, causing some dilution to its existing shareholders; however, the merger is expected to help the merging companies secure financial stability, mitigate risk, and improve operating efficiency and competitiveness, positively affecting shareholder value.

4. Merger ratio SK Innovation Co., Ltd. : SK IE Technology Co., Ltd. = 1 : 0.1174540 The reference share price for the merger ratio was calculated as the arithmetic average of the weighted arithmetic average closing price over the most recent 1 month, the weighted arithmetic average closing price over the most recent 1 week, and the most recent closing price, calculated as of the day before the board resolution date for the merger (August 24, 2026).

5. Basis for calculating the merger ratio As merging companies SK Innovation Co., Ltd. and SK IE Technology Co., Ltd. are affiliated companies both listed on KOSPI, the merger value was calculated under Article 176-5, Paragraph 1, Item 1 of the Enforcement Decree of the Financial Investment Services and Capital Markets Act, and the merger ratio was derived from that value. a. Merger value of surviving company SK Innovation Co., Ltd.'s common shares: calculated as of the day before (August 24, 2026) the earlier of the board resolution date (August 25, 2026) and the merger agreement date (August 26, 2026), as the arithmetic average of the volume-weighted arithmetic average closing price over the most recent 1 month, the volume-weighted arithmetic average closing price over the most recent 1 week, and the most recent closing price, with no premium or discount applied. - 1-month weighted average closing price (July 27, 2026 - August 24, 2026): KRW 118,611 - 1-week weighted average closing price (August 18, 2026 - August 24, 2026): KRW 128,874 - Most recent closing price (August 24, 2026): KRW 130,100 - SK Innovation Co., Ltd. merger value: KRW 125,862 b. Merger value of dissolving company SK IE Technology Co., Ltd.'s common shares: calculated the same way, as of the same reference date. - 1-month weighted average closing price (July 27, 2026 - August 24, 2026): KRW 14,364 - 1-week weighted average closing price (August 18, 2026 - August 24, 2026): KRW 14,676 - Most recent closing price (August 24, 2026): KRW 15,310 - SK IE Technology Co., Ltd. merger value: KRW 14,783 Accordingly, the merger ratio was determined as 1 : 0.1174540 (SK Innovation Co., Ltd. : SK IE Technology Co., Ltd.). - Corporate value: surviving company 21,277,322,003,256; dissolving company 1,209,058,699,300

6. External appraisal Not applicable. Basis and reason: As this merger is between affiliated companies both listed on KOSPI, the merger value was calculated based on the market reference price for common shares under Article 165-4 of the Capital Markets Act and Article 176-5, Paragraph 1, Item 1 of its Enforcement Decree, so no external appraisal institution's evaluation is required. Name of institution: -; appraisal period: -; appraisal opinion: -

7. Type and number of new merger shares (shares) Common shares: 4,481,300; preferred shares: -

8. Merger counterparty Company name: SK IE Technology Co., Ltd. (SK ie technology Co., Ltd.) Main business: Manufacture of primary and secondary batteries Relationship with the Company: Subsidiary Most recent fiscal year financial details (KRW): Total assets: 4,391,860,993,723 Capital: 81,787,100,000 Total liabilities: 1,790,415,728,574 Revenue: 261,874,277,718 Total equity: 2,601,445,265,149 Net income: -211,417,928,464 External audit: Hanyoung Accounting Corporation, opinion unqualified; representative, date of incorporation, head office, expected securities registration filing date for a SPAC-dissolution merger: not applicable, -

9. Newly incorporated merger company: all items -; relisting application: Not applicable

10. Merger schedule Merger contract date: August 26, 2026 Record date for determining shareholders: September 9, 2026 Shareholder register closure period: - Period for receiving notices of opposition to merger: September 9, 2026 - September 23, 2026 Expected general shareholders' meeting date: - Appraisal rights exercise period: - Old share certificate submission period: - Expected trading suspension period: - Creditor objection period: November 24, 2026 - December 24, 2026 Merger date: January 1, 2027 Closing report general meeting date: January 4, 2027 Expected merger registration date: January 4, 2027 Expected date of delivery of new share certificates: - Expected listing date of new shares: January 18, 2027

11. Backdoor listing: Not applicable 12. Whether another company's backdoor listing requirements are met: Not applicable

13. Appraisal rights Exercise requirements: As this merger proceeds under the small-scale merger procedure, appraisal rights are not granted under Article 527-3 of the Commercial Act. Expected purchase price: -; exercise procedure, method, period, location: -; expected payment timing and method: -; restrictions on appraisal rights: -; effect on the contract: -

14. Board resolution date (decision date): August 25, 2026 - Independent (outside) directors present: 6, absent: 0 - Attendance of auditor (audit committee member who is not an independent (outside) director): -

15. Put option or similar contracts: No; contract details: -

16. Subject to securities registration statement: Yes; reason for exemption, if applicable: -

17. Future plans for corporate restructuring As of the date of this report, no confirmed plans for corporate restructuring are in place. However, through this merger, the merging companies are reviewing measures to improve operating efficiency and reduce costs by integrating the organizations and functions of both companies, including consolidating management functions duplicated by operating as separate listed companies, streamlining the separator business structure, and concentrating R&D and operating resources on core business.

18. Other important matters relevant to investment decisions a. This disclosure is the confirmed disclosure superseding the Company's June 10, 2026 disclosure responding (unconfirmed) to a rumor or media report. b. As this merger proceeds as a small-scale merger under Article 527-3 of the Commercial Act, surviving company SK Innovation Co., Ltd.'s shareholders are not entitled to appraisal rights, and the shareholders' meeting for merger approval is replaced by board resolution. (Expected board resolution date replacing the merger-approval shareholders' meeting: November 24, 2026.) c. Under Article 527-3, Paragraph 4 of the Commercial Act, if shareholders holding 20% or more of the surviving company's total issued shares notify in writing their opposition to the merger within two weeks of the merger announcement date, this merger cannot proceed as a small-scale merger. If grounds for disqualification arise, the merger may proceed under the formal merger procedure of Article 522 of the Commercial Act, disclosed accordingly. d. This merger will proceed by the surviving company issuing new shares to the dissolving company's shareholders; other than payment for odd-lot shares, no merger consideration or other cash will be paid to the dissolving company's shareholders. e. The "7. Type and number of new merger shares" above may change depending on the results of SK IE Technology Co., Ltd. shareholders' exercise of appraisal rights and the handling of odd-lot shares. f. The "8. Merger counterparty" financial details above are based on SK IE Technology Co., Ltd.'s consolidated financial statements as of the end of 2025. g. The "10. Merger schedule" above is the expected schedule as of the date of submission of this report and may change due to permits/approvals under relevant laws and consultation with relevant authorities. h. The closing report meeting in "10. Merger schedule" above will be replaced, under Article 526, Paragraph 3 of the Commercial Act, by the board's merger-closing report resolution and announcement on January 4, 2027. i. Any odd lot of less than one share arising from the allotment of new merger shares will be paid in cash based on the closing price on the listing date of the new merger shares, and will be acquired as treasury stock by the surviving company under Article 341-2, Item 3 of the Commercial Act. j. No new merger shares will be allotted for common shares of the dissolving company held by the surviving company, or for treasury shares the dissolving company comes to hold due to its shareholders' exercise of appraisal rights; as of the date of this report, SK IE Technology Co., Ltd. holds no treasury shares. k. The surviving company is, as of the date of this report, a KOSPI-listed corporation and will maintain that status after the merger. l. As the dissolving company's shareholders' meeting resolution approving the merger agreement is a special resolution matter, this merger may fail if it does not obtain approval of at least two-thirds of the voting rights of shareholders attending and at least one-third of the total issued shares. m. Under Article 11, Paragraph 1, Item 4 of the amended Monopoly Regulation and Fair Trade Act (effective August 7, 2024), a merger between a parent and subsidiary is excluded from domestic business combination reporting. Vietnam requires business combination reporting under its laws, and the Company plans to submit a filing to the Vietnamese competition authority after the board resolution approving execution of this merger agreement; it will take action under other countries' laws as needed. n. The conditions precedent and termination conditions in the merger agreement are summarized as follows. Article 12 (Conditions precedent): the merging companies' obligation to carry out the merger is subject to satisfaction, by the merger date, of lawful board/shareholders' meeting approval of the agreement and merger; completion of material domestic and overseas government approvals, permits and reporting procedures, including business combination filings; and absence of any amendment to laws, government order, or court decision prohibiting or materially restricting the merger after the agreement date. Article 15 (Amendment and termination): the merging companies may terminate the agreement at any time by written agreement before the merger date; the surviving company may terminate by written notice within two weeks of the small-scale-merger-opposition deadline if grounds for disqualification as a small-scale merger arise (unless it has notified intent to proceed via formal merger procedure); the parties may by written agreement terminate or amend terms if the aggregate appraisal-right purchase price exceeds KRW 350 billion for the dissolving company's shareholders, or (where proceeding via formal merger procedure) KRW 600 billion for the surviving company's shareholders; the parties may amend terms or terminate by written notice if a material unforeseen adverse change, defect or insolvency arises; either party may terminate by written notice if a required government approval is conclusively denied; and either non-breaching party may terminate by written notice if the other party's representations/warranties are inaccurate or it breaches its obligations and fails to cure within 7 business days of a cure request. o. The "corporate value" in "5. Basis for calculating the merger ratio" above was calculated by multiplying the merger value by the total number of issued shares, under Article 5-13-2 of the Regulation on Issuance and Disclosure of Securities; the surviving company's corporate value is based on common shares only, not considering preferred shares. p. The expected merger registration date of January 4, 2027 in "10. Merger schedule" above is the expected date of filing the merger registration application. q. In connection with directors' duty of loyalty under Article 382-3 of the Commercial Act and the Ministry of Justice's recommended special-committee practice, SK Innovation Co., Ltd. established a special committee composed solely of 6 independent directors. SK Innovation Co., Ltd.'s board resolved on May 27, 2026 to establish the special committee and adopt its rules, and the committee held six meetings over roughly three months, from May 27, 2026 to August 25, 2026, reviewing the management necessity, appropriateness of transaction terms and procedural adequacy of the merger. SK Innovation Co., Ltd. retained legal advisor Kim & Chang and financial advisor Samil PwC, who advised on the merger's legality, procedural legitimacy, the fairness of the merger value and ratio, and shareholder protection procedures. Based on this review, the special committee resolved unanimously that the legitimacy of the transaction's purpose, the fairness of its terms and the adequacy of its procedure were secured, and reported this to the board. The board, considering the special committee's and external experts' review, determined that the merger serves the interests of the Company and all shareholders, the merger ratio was calculated under relevant law and verified by external appraisal, and the Ministry of Justice guidelines' fairness-enhancing measures were implemented, and accordingly approved execution of this merger agreement. For details, please refer to the board minutes and board opinion attached to this report.

Related disclosure: 2026.06.10 Response (unconfirmed) to rumor or media report For further details, please refer to SK Innovation Co., Ltd.'s securities registration statement (merger) filed on August 26, 2026.